On the Relevance of Sharp Gamma-Ray Features for Indirect Dark Matter Searches

TL;DR

Sharp gamma-ray spectral features near the dark matter particle mass can greatly enhance the sensitivity of indirect detection methods, providing a more effective way to constrain dark matter properties than broad spectral features.

Contribution

The paper demonstrates that spectral features close to the dark matter mass improve gamma-ray telescope sensitivity and derives projected limits on these features, including line signals.

Findings

Spectral features near dark matter mass enhance detection sensitivity.

Projected limits on gamma-ray spectral features are significantly improved.

Sharp features outperform broad spectral features in constraining dark matter.

Abstract

Gamma rays from the annihilation of dark matter particles in the Galactic halo provide a particularly promising means of indirectly detecting dark matter. Here, we demonstrate that pronounced spectral features at energies near the dark matter particles' mass, which are a generic prediction for most models, can significantly improve the sensitivity of gamma-ray telescopes to dark matter signals. We derive projected limits on such features (including the traditionally looked-for line signals) and show that they can be much more efficient in constraining the nature of dark matter than the model-independent broad spectral features expected at lower energies.